On a problem of ultrasonic tomography

The aim of this paper is to solve inverse coefficient problems for wave equations. A method based on the direct computation of the gradient of the residual functional by solving the conjugate problem for a partial differential equation is proposed. Some results of computer simulations are discussed. It is shown that the method is high efficient. These results allow us to make a further progress in the development of high-resolution 3D ultrasonic tomographs.